Jesus's vision(Rev 1;1) transcribed thru John, denotes to the Seven Churchs of Asia that "they" countenanced the Synagogue of Satan.. Thereby equating the/a synagogue and a church..
A synagogue was an illegal temple since they had no ARK of the Convenant(or GOD), anymore.. When "the Church" took on the attributes of a synagogue, as they do now and then somewhat.. ALL of them.. The difference is marginal..
The Synagogue of Satan is a harsh description but it is probably the most accurate.. Not only of RCC and EO practices but of most Protestant applications also..
Must be Satan loves church buildings and 501c tax free corporations.. OH! and the STAFF to run said synagogues.. You know, Nicolaitans...
Thanks for the important points . . . quite valid, I think.